Re: [gentoo-user] Do I really need to install new packages during upgrade?

[Gevisz]

On Tue, 26 Aug 2014 13:30:58 +0200
Alan McKinnon <alan.mckinnon@×××××.com> wrote:

> On 26/08/2014 12:00, Gevisz wrote:
> > On Tue, 26 Aug 2014 10:42:01 +0100
> > Peter Humphrey <peter@××××××××××××.uk> wrote:
> >
> >> On Tuesday 26 August 2014 12:21:35 Gevisz wrote:
> >>> I have just tried to upgrade my system (which I do almost every
> >>> day) and found out that portage wants to install 6 new python
> >>> packages that seem to be unnecessary because for example
> >>>   # equery depends dev-python/pyopenssl
> >>> reports that no other package depends on this one.
> >>>
> >>> The same situation is with all the other python packages.
> >>>
> >>> # emerge --update --deep --with-bdeps=y --newuse --backtrack=60
> >>> --ask world
> >>
> >> It could be that "--with-bdeps=y" term. I took a long time to learn
> >> that lesson, as old-timers may remember.
> >>
> >> What happens if you change y to n?
> >
> > In this case, the portage wants to update all the same "unnecessary"
> > python packages and only decides not to update the eselect-ruby.
>
>
> You've approached this in an inefficient way.
>
> When portage gives an odd list of dependencies to be emerged
> (especially if they are new indicated by [ebuild  N     ]), then
> always run emerge with the -t option. This will display the same
> output in a tree view showing you what pulls things in. This exactly
> answers the question you asked.

Thank you for the hint. I will try it next time but now
  # emerge -t pyopenssl
just re-emerged the package and I saw no dependencies.

> Looking at emerge output without the -t option does not show this
> information, so you don't know.
>
> When a package is to be installed new (i.e. not an update) then
> "equery depends" is pointless. That form of the command shows the
> dependencies for *installed*packages*, so obviously can't show the
> deps for something not installed yet.

Yes, now "equery depends" shows that pyopenssl is needed for ssl-fetch
and ndg-httpsclient, ssl-fetch is needed for mirrorselect is needed for
nothing. :)

I do not remember installing mirrorselect, at least I never used it
(just now found out what it is used for) but somehow it managed to get
into my world file...

May be I used it during my first Gentoo installation, my birth as Gentoo
user. We usually do not remember what happened during our births. :) 

> There are options to equery that make it search the tree itself,
> not your vdb, but they are slo-o-o-ow. maan equery for details.

I am not in a hurry, so will look for this option too. :)
 
> --with-bdeps=n omits eselect-ruby as it is a build depend for some
> package. A build depend means you need it to build something not to
> run it. Portage defaults to n on this to make things a little more
> efficient and compile less stuff. In your case eselect-ruby will only
> be updated when something else that needs it at build time is
> updated. Until then you strictly speaking don't really need it to be
> updated.

Thank you for the explanations.